Carbonate Stratigraphic Correlation And Favorable Reservoir Prediction Of Ordovician In Tahe District IV

Tahe district IV is located in Akekule Heave of Northern Tarim Basin. Carbonate reservoir mainly concentrates in Ordovician. Limited by the resolution of logging data and seismic data, little research has been conducted in stratigraphic division and correlation of carbonate reservoir of the pores and fractures type, which causes karstification reservoir correlation and research on geological model have to use the same thickness, it is far from sufficient to meet the requirements of fine reservior description in oil field development. Some changes in carbonate reservoir lithology and physical properties have?the characteristics of voluntariness mutagenicity, which made it more difficult to predicte using seismic data, and seriously hindered the effects of oilfield exploitation.The main purpose of this paper is to establish high frequency cycle stratigraphic framework of the upper Yingshan Formation of middle-lower Ordovician in Tahe district IV, based on the classification of high frequency cycle; and search for reservoir prediction technique for carbonate reservoir characterized by deep burial depth and very high heterogeneity.Based on the core data, thin section data, borehole data, well logging data and seismic data, the paper studied petrologic features of Ordovician in Tahe district IV and the distribution of sedimentary facies of the upper Yingshan Formation. The conclusion is that the main reservoir spaces in Tahe district IV are mainly fractures, holes, caves; The main type of the reservoir includes cave reservoir, fracture-hole reservoir, fracture reservoir .Based on study of reservoir characteristics, using INPEFA technique established high frequency cycle stratigraphic framework in the upper Yingshan Formation, and studied the characteristics and its distribution of Karstification reservoir within the correlation framework.Under the guidance of the geological research, paleogeomorphology has been approximately restored of the top of middle-lower Ordovician in Tahe district IV using high-resolution 3-D seismic data, and it further investigated the distribution characteristics of paleogeomorphology. Applying techniques of coherent analysis, discontinuity detection, curvature analysis predicted the development zones of ancestral river, fault and the fracture, and then clarified their development characteristics of the top of middle-lower Ordovician in Tahe district IV. Finally, the paper explores seismic attributes reservoir prediction techniques. The research inticates multiple attribution cluster analysis can predicte favorable zones for the development of reservoir, spectral decomposition technique can find out the distribution characteristics of holes and caves. logging-constrained inversion technique has the special advantages in the aspect of predicting the larger caves.The innovations in the dissertation as bellow: 1 Applying INPEFA technique established high frequency cycle stratigraphic framework of the upper Yingshan Formation of middle-lower Ordovician in Tahe district IV for the first time. 2 The distribution characteristics of karst reservoir are studied whithin high frequency cycle stratigraphic framework. 3 Applying techniques of coherent analysis, discontinuity detection, curvature analysis, multiple attribution cluster analysis, spectral decomposition, log-constrained inversion predicted favorable reservoir zones, and formed a technique of carbonate reservoir prediction.